The invention relates to a charge-coupled semi-conductor device having a plurality of electrodes for storing and transporting information-carrying charge, these electrodes being in the form of coplanar silicon strips which are formed from a single silicon layer and are located on an insulating layer and are mutually separated by grooves filled at least in part with silicon oxide and having a width of at most 1 .mu.m, which is narrower than the silicon strips.
The invention further relates to a method of manufacturing such a device.
A charge-coupled semiconductor device of the kind described above and a method of manufacturing such a device are known from U.S. Pat. No. 4,449,287.
The method according to that U.S. patent specification permits manufacturing charge-coupled semi-conductor devices having very small memory cells, in which the electrodes used for the charge transport are located at a very small relative distance (less than 1 .mu.m) and in one plane so that they need not overlap each other. The electrodes are mutually separated by very narrow grooves or slots, which are most often thermally oxidized. The grooves are so narrow that they are often filled completely with oxide.
Apart from the electrodes used for charge storage (designated hereinafter as storage electrodes), one or more other electrodes are often required in a charge-coupled semiconductor device, normally designated as CCD (short for "Charge-Coupled Device"). These electrodes, which are designated as transfer electrodes, are not used for charge storage, but are intended to cause the potential to vary in the direction of the charge transport in such a manner that the charge is transported in the desired direction.
Such transfer electrodes are located between the storage electrodes, and consequently require an additional amount of space. Moreover, they are often at least in part situated in a plane different from that of the storage electrodes. Since in the method according to U.S. Pat. No. 4,449,287 the smallest possible dimensions per memory cell are aimed at, this may be a great disadvantage. If the transfer electrodes are not located in the same plane as the storage electrodes, step coverage problems may additionally arise during the metallization process.